package libwmf0.2-7 0.2.8.4-6.1ubuntu2 failed to install/upgrade: defoma-app breaks across perl transition

I think the root cause is:

Preparing to replace libwmf0.2-7 0.2.8.4-6.1ubuntu2 (using .../libwmf0.2-7_0.2.8.4-8.1ubuntu1_i386.deb) ...
Can't locate File/Copy.pm in @INC (@INC contains: /etc/perl /usr/local/lib/perl/5.10.1 /usr/local/share/perl/5.10.1 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.10 /usr/share/perl/5.10 /usr/local/lib/site_perl .) at /usr/bin/defoma-app line 7.
BEGIN failed--compilation aborted at /usr/bin/defoma-app line 7.
dpkg: warning: subprocess old pre-removal script returned error exit status 2
dpkg - trying script from the new package instead ...
dpkg: error processing /var/cache/apt/archives/libwmf0.2-7_0.2.8.4-8.1ubuntu1_i386.deb (--unpack):
 there is no script in the new version of the package - giving up
Selecting previously unselected package libgdk-pixbuf2.0-0.
dpkg: considering deconfiguration of libwmf0.2-7, which would be broken by installation of libgdk-pixbuf2.0-0 ...
dpkg: yes, will deconfigure libwmf0.2-7 (broken by libgdk-pixbuf2.0-0).
Unpacking libgdk-pixbuf2.0-0 (from .../libgdk-pixbuf2.0-0_2.24.0-1ubuntu2_i386.deb) ...
De-configuring libwmf0.2-7 ...

Status changed to 'Confirmed' because the bug affects multiple users.

This bug was fixed in the package libwmf - 0.2.8.4-10ubuntu1

---------------
libwmf (0.2.8.4-10ubuntu1) precise; urgency=low

  * Resynchronise with Debian. Remaining changes:
    - Split out GTK plugin into separate package.
  * Add a no-op prerm to libwmf0.2-7 to work around old prerms breaking on
    upgrade due to using defoma while perl-modules is unconfigured
    (LP: #904901). This can be removed after Ubuntu 12.04 LTS.

libwmf (0.2.8.4-10) unstable; urgency=low

  * Read libwmf binary package name from control in rules.
  * Switch to dh instead of cdbs; bump debhelper compat to 9 and debhelper
    build-dep to >= 8.9.4~; this also means multiarch, so update install files
    and rules to cope with new pathnames. Add new 05_gdk-pixbuf-loader-dir
    patch to fix the install location for the module to be under
    gdk-pixbuf-2.0 and not gtk-2.0. Add ${misc:Pre-Depends}.

libwmf (0.2.8.4-9) unstable; urgency=low

  * Ack Neil Williams's NMU; thanks!
  * Stop shipping .la files altogether; remove dependency_libs stripping code
    from rules; rdepends of libwmf-dev either dont ship any .la files or ship
    .la files which don't reference the libwmf one.
  * Add comment to debian/libwmf0.2-7.lintian-overrides to point at
    Debian #382511.
  * Update my email address in control.
  * Drop defoma support from the packaging; closes: #542336; based on patch
    from Christian Perrier; thanks! Defoma support is also included in the
    upstream configure.{ac,in}, but is largely useless nowadays, at least the
    generated libwmf XML fontmap in /var/lib/defoma/libwmf0.2-7.d/fontmap
    doesn't list any actual font on my system.
    - Drop defoma build-dep and dep.
    - Stop shipping a var/lib/defoma/libwmf0.2-7.d directory and "rm -rf"
      it on upgrades of libwmf0.2-7.
    - Drop debian/defoma XML fontmap generation script which seems to be
      generating an empty XML fontmap nowadays; incidentally closes: #501871.
    - Stop passing --with-fontdir=/var/lib/defoma/$(libwmf_pkg).d and
      --with-gsfontdir=/var/lib/defoma/$(libwmf_pkg).d to configure; these are
      going away and didn't have any font files anyway.
    - Review fontdir, gsfontdir, sysfontmap, gsfontmap and xtrafontmap
      configure args:
      . sysfontmap is the default XML fontmap (when not specified via the API)
        and currently points at an empty XML list of fonts; this is parsed
        either by libexpat1 or libxml2; in both cases, no specific message is
        output by default if the file is missing. The configure.ac default
        for this file is /usr/share/fonts/fontmap which has a change of
        existing with random data some day, so just set it to /non-existent.
      . xtrafontmap is similar to sysfontmap and serves asan extra fontmap on
        top of the system one. It's also used by thelibwmf-fontmap tool which
        serves generation of fontmap XML files and isn't shipped nor used
        during build. Keep xtrafontmap set to /etc/libwmf.fontmap to allow
        for local configuration.
      . gsfontmap is similar to sysfontmap except it points at a
        GhostScript-style Fontmap. It seems sensible to point libwmf at
       ...